WASHINGTON — Defense Secretary Robert Gates plans to ask Congress on Tuesday for permission to shift as much as $1.3 billion from other military programs to speed up the purchase of bomb-resistant vehicles for U.S. troops in Iraq.

According to military officials, the Army would like to reallocate about $800 million, and the Marines want roughly $500 million, to buy the Mine Resistant, Ambush Protected (MRAP) vehicles that have saved lives in roadside bomb attacks.

Gates is expected to go to Congress with senior Army and Marine leaders to formally request that the money be reprogrammed, the officials said on condition of anonymity because the meeting has not yet taken place.

Military officials said the shift in funds would not affect any day-to-day war spending or the troops in battle.

The Pentagon has come under fire in recent months, particularly from Congress, for perceived delays in getting armored vehicles to the troops.

Gates has said that getting them more of the armored vehicles is a top priority. And he has demanded an accelerated effort to get them to Iraq in large numbers to replace the more vulnerable Humvee utility vehicle used by soldiers and Marines.

The additional money would help contractors get more of the vehicles to the field faster, the officials said. They did not say exactly how many more or how much faster the work could be done.

On July 11, the Pentagon’s Joint Requirements Oversight Council, which includes high-ranking representatives from all of the military services, agreed that the military needs to buy as many of the reinforced vehicles as the contractors could churn out.

The group previously endorsed the need for nearly 7,800 MRAPs, which included about 2,500 for the Army. The projected cost would be about $8.4 billion.

Army officials have said they could use as many as 17,700 and the Marines want 3,700.

In its memo, the council said the Pentagon wants to “reach a maximum production rate as soon as possible,” but the final number to be bought will depend on the changing conditions in the war, feedback from commanders and any possible changes in the military’s mission in Iraq.

To date, no U.S. forces have been killed while riding in the MRAP carriers, which cost about $1 million each and have a unique V-shaped hull that deflects blasts outward and away from passengers. They are considered lifesavers against the No. 1 killer in Iraq — roadside bombs.

The military officials said it is hoped that Congress would eventually restore much of the funding, which is being shifted from other accounts for the fiscal year that ends Sept. 30. A significant amount of the money for the Army, for example, was initially earmarked for maintenance and refurbishment of equipment that was scheduled to come back to the U.S. with units that had planned to come home after one-year deployments.

Gates, however, extended the Iraq tours to a maximum of 15 months, and as a result there have been savings in some of those repair accounts.